物理化学学报 >> 2002, Vol. 18 >> Issue (04): 340-345.doi: 10.3866/PKU.WHXB20020411

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超级活性炭的合成及活化反应机理

邢伟;张明杰;阎子峰   

  1. 石油大学重质油加工国家重点实验室,中国石油天然气集团公司催化重点实验室,东营　257061
  • 收稿日期:2001-08-22 修回日期:2001-11-02 发布日期:2002-04-15
  • 通讯作者: 阎子峰 E-mail:zfyancat@mail.hdpu.edu.cn

Synthesis and Activation Mechanism of Coke Based Super Activated Carbons

Xing Wei;Zhang Ming-Jie;Yan Zi-Feng   

  1. State Key Laboratory for Heavy Oil Process,The Key Laboratory of Catalysis,CNPC,University of Petroleum,Dongying　257061
  • Received:2001-08-22 Revised:2001-11-02 Published:2002-04-15
  • Contact: Yan Zi-Feng E-mail:zfyancat@mail.hdpu.edu.cn

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摘要： 以石油焦为原料,采用碱熔活化法合成出具有超高比表面的超级活性炭.借助XRD、TGDTA、N2吸附实验等手段,对其结构与性能进行了表征.同时,设计原位TGDTA测试技术、反应快速终止技术,对超级活性炭合成机理进行了考察,提出了两段活化反应机理,即中温径向活化机理和高温横向活化机理.发现K2O、－O－K＋以及－CO－2K＋是径向活化为主的中温活化段的活化剂活性组分,而处于熔融状态的K＋O－、K＋则是横向活化为主的高温活化段的催化活性组分.并发现径向活化是超级活性炭形成发达微孔分布的主要途径,也是控制超级活性炭微孔分布的主要手段.而高温横向活化机理则是导致超级活性炭形成大孔的主要途径.高温横向活化与中温径向活化一起构成石油焦基超级活性炭形成的主要机理.

关键词: 超级活性炭, 活化机理, KOH, 径向活化, 横向活化

Abstract: Coke based super activated carbons (SAC) with higher surface area were synthesized by means of KOH thermoactivation.The structure and properties of SAC samples were extensively investigated by TGDTA and N2 adsorption techniques.Simultaneously,insitu TDDTA and quick activation quenching techniques were designed to investigate the activation mechanism of SAC samples.A twostep activation mechanism,which includes radial activation at moderate temperature and transverse activation at higher temperature,respectively,was tentatively postulated.It indicated that K2O,－O－K＋ and －CO－2K＋ might be the active sites of radial activation at moderate temperature and fused K＋O－ and K＋ might be the active centers of transverse activation at higher temperature.Of special is that radial activation at moderate temperature may result in the formation of micropores and that this might be the effective way to improve the micropore distribution of SAC samples.In contrary,the transverse activation at higher temperature would lead to the formation of macropore.The formation of super activated carbons was resulted from the radial activation at moderate temperature and subsequent transverse activation at higher temperature.

Key words: Super activated carbons, Activation mechanism, KOH, Radial activation, Transverse activation